A delta-sigma modulator is configured to include a loop filter and a quantizer (refer to Non Patent Literature 1). The loop filter is a dual-input system, and an input signal to the delta-sigma modulator is inputted to one of two inputs of the loop filter while an output of the quantizer is fed back to the other input.
An output of the loop filter is provided to the quantizer. The quantizer quantizes the output of the loop filter to generate an output signal (quantized signal), and outputs the signal.